Sound reproducer



June 2, 1925 1,540,229

H. SCHARF SOUND REPRODUCER Filed Oct. 27. 1925 ML/mg N, R. fizz umPatented June 2, 1925. 1

UNITED I v I HANs SCHmRI-IN, M

SOUND anrnonocna.

Application filed October 27, 1923. Serial No. 671,148.

speakers and the like.

present In devices of this character the diaphragm is usually discshaped and is held around its periphery. A drawback of such devices isthat not the entire surface of the diaphragm is exposed to the air.Furthermore, during its movement the diaphragm produces objectionablenoises because it is rigidly held around its periphery.

In accordance with the present invention these drawbacks are avoided byholding the diaphragm around its periphery in a manner that thediaphragm contacts only with some soft material preferably rubber andthat the whole surface of the diaphragm is exposed to the air. Thediaphragm provided in accordance with the present invention movespractically freely in the air and substantially parallel with its normalposition. This will result in improving the quality and quantity of thereproduced sound.

The soft' material e. g. rubber, used for holding the diaphragm ispreferably stretched over the whole surface of the diaphragm or it maybe solidly connected therewith around its periphery. Due to theprovision of such rubber pad the vibration of the diaphragm will bematerially damped. Preferably, the diaphragm is cone-shaped whereby thecreased notwithstanding the fact that the cross section of the holdingarrangement remains the same. One of the advantages of the diapl'iragn'iforming the object of the um-ision of the soft material used forclamping the diaphragm the latter makes no contact with metal.

The drawings show a diaphragm constructed in accordance with the presentin rention, Fig. 1 being a sectional view, and Fig. 2 a top plan view.

In the arrangement shown in the drawings a diaphragm 1 is made of acone-shaped Sheet of aluminum or some other rigid masurface of thediaphragm is in-' invention consists in that due to the PATENT orrics.

terial which in any well known manner, e. g. through the agency of a rod2, is caused to vibrate. The metallic cone is entirely covered with apiece of fiat rubber 3 which projects beyond the periphery of the diaphragm. lhe projecting rubber rim 4 is wrapped around a .ring 5 ofresilient material and is forced therewith into a suitably shaped frame'6. The diaphragm 1 is attached to the rubber cover 3 by means of aplurality of small rivets 7 provided around its periphery. The frame 6is provided with projections 8 by means of which it may be attached to atable or panel. It will be seen from the drawings that the diaphragm 1is nowhere in contact.with metal, that it moves substantially parallelto its normal position, and that substantially the entire surface of thediaphragm is exposed to the air. The rubber coating will entirelyeliminate the natural vibrations of the diaphragms.

Obviously, certain features of the invention may be practised with aflat diaphragm as well as a cone-shaped diaphragm. Instead of usingrubber for covering the diphragm some other soft substance may be -used.Furthermore, two cone-shaped diaphragms like .the one shown in thedrawings may be combined into a double cone. These and othermodifications as well as. various applications of the invention tocommercial structures will readily suggest themselves to those skilledin the art.

lVhat is claimed is:

1. A sound reproducer comprising a vi.- bratory diaphragm, a sheet ofresilient material engaging and extending over one face of the diaphragmand beyond the periphery thereof, and a. support encircling thediaphragm and of greater size than the diaphragm, said sheetadjaccnt itsperiphery being secured to said support.

2. A sound reproducer comprising a vibratory diaphragm, a sheet ofresilient mate-- rial engagingand extending over one face of thediaphragm, said sheet beingafiixed to the diaphragm adjacent theeriphery of the diaphragm and extending eyond said periphery, and asupport encircling the diaphragm and of greater size than saiddiaphragm, and means for engaging the sheet adjacent its periphery forafiixing it to said support.

3. A sound reproducer comprising a vibratory diaphragm, a sheet ofresilient malatter, said support having an annular reterial'engaging andextending over one face cess and a fastening ring to press the peof saiddiaphragm, a clamping ring securing riphery of the sheet into saidrecess to mount the sheet to the diaphragm adjacent th the diaphragmwith the sheet upon said sup- 5 periphery, and a support encircling theP b d id periphery, a support f grea In testimony whereof I affix mysignature.

size than the diaphragm and encircling t e DR. HANS SCH/ARR

